Dissolving CaCl2 in Water Concepts

The video explains what happens when calcium chloride (CaCl2) is added to water (H2O). It describes the dissociation of CaCl2 into calcium ions (Ca2+) and chloride ions (Cl-) in water, highlighting the ionic nature of the process. The video also covers how to write the chemical equation for this process, including the use of the 'aq' symbol to denote dissolved ions. It concludes by discussing whether this process is a chemical reaction or a physical change, noting its reversibility.

What happens to the charges of calcium and chlorine when CaCl2 is added to water?

• Both calcium and chlorine become positively charged.

• Both calcium and chlorine become neutral.

• Calcium becomes positively charged and chlorine becomes negatively charged.

• Calcium becomes negatively charged and chlorine becomes positively charged.

What type of ions are formed when CaCl2 is dissolved in water?

• Hydrogen ions

• Ionic ions

• Metallic ions

• Covalent ions

What is the charge of the calcium ion in the solution?

• 2+

• 2-

• 1+

• 1-

What is the coefficient of Cl- ions in the dissociation equation of CaCl2?

• 1

• 4

• 2

• 3

Why do chemists write 'aq' after ions in a solution?

• To specify the ions are in a liquid state.

• To denote the ions are solid.

• To show the ions are dissolved in water.

• To indicate the ions are in a gaseous state.

What does the equation for CaCl2 in water represent?

• A biological process

• A nuclear reaction

• A physical change

• A chemical reaction

What happens if the solution of CaCl2 in water is left out?

• The solution becomes acidic.

• The solution turns into a gas.

• The water evaporates, leaving CaCl2 behind.

• The solution becomes more concentrated.

How is the process of dissolving CaCl2 in water often classified?

• As a chemical reaction

• As a nuclear change

• As a physical change

• As a biological change